Some breast cancers depend on female hormones, such as oestrogen, to grow. Hormone therapy can slow down – or even stop - this growth by blocking the production of these hormones, or reducing the ability of cancer cells to respond to them.
Hormone treatment courses are often taken over a period of months or years, with regular check-ups along the way. They are often combined with chemotherapy courses, reducing the risk of an existing cancer spreading and a new one developing.
To find out if hormone therapy will work for you, a receptor test will be carried out to see if your cancer is the hormone sensitive type. Around 3 out of 4 of women diagnosed with the disease have the hormone sensitive form. If the test shows that yours is hormone sensitive, you will be advised to have hormone treatment.
The drugs
Tamoxifen is commonly used to treat hormone sensitive early breast cancer. Side effects can include weight gain and menopausal symptoms such as hot flushes. Tamoxifen can also increase the risk of blood clots, also known as thrombosis, and cancer of the womb lining, known as endometrial cancer. These, though, are rare.
Aromatase inhibitors are for post-menopausal women with hormone sensitive breast cancer. Menopausal symptoms such as hot flushes, vaginal dryness and tiredness can arise from taking aromatase inhibitors. You may also feel a bit sick, get headaches or diarrhoea and experience generalised muscular pains.
You may be prescribed just one of these drugs, or tamoxifen followed by an aromatase inhibitor.
Hormone treatments for breast cancer are completely different to hormone replacement therapy (HRT) used to treat menopausal symptoms.
There’s more information about specific hormone therapy drugs, their benefits, and their possible side effects on the Cancer Research UK website.
